Sleeve and method for making same



' June 3 1941. c. H. KLEIN SLEEVE-AND METHOD FOR MAKING SAME Filed Jan.4, 194g) INVENTOR. bar/e; h. WEI/7 BY/OZ ATTORNEY. I

Patented June 3.1941 Q UNITED STATESQPATENT OFFICE SLEEVE AND METHOD FORMAKING SAME Charles H. Klein, Cleveland, Ohio, aasignor to The NationalTelephone Supply Company Application January 4 11940, Serial No. 31.2 i

'lClaims.

My invention relates to a device for joining metal wires together andmore particularly to a metal sleeve which is adapted to firmly grip theends oi the wires to be joined and which has a high electricalconductivity between-the wires to be Joined and the metal sleeve.

An object of my invention is to provide an internal coating for a-sleevewhich coating has an electrical conductivity equivalent substantiallyequal to that of the wire to be fastened in the sleeve.

An object of my invention is to provide a device for joining the ends oftwowires together in a union which is sumciently strong to withstand apull on one wire with respect to the other and which has a highelectrical conductivity.

Another object of my invention is to provide a metal sleeve foranchoring the end of an electrical conductor and to increase theelectrical conductivity between the sleeve and the wire withoutmaterially decreasing the strength of the connection between the sleeveandthe wire.

Still another object of my invention is to provide a wireattachingsleeve which has a coating on the inner surface thereof.

Still anotherobject of myinvention is to coat the inner surface of anattaching sleeve with a plurality of substances, one of which increasespreparatory for coating the inside surifaces oi with one connectingsleeve being more predominately shownthan the others, together with aspray gun for coating the sleeves.

Figure 3 is a cross sectio'nai view connecting sleeves as coated. v

Figure 4 is a longitudinal cross-sectional view of Figure 3 and -shpws awire positioned to be inserted through an open end thereof.

of one of my Figure 5 is a longitudinal cross-sectional view showing thewire inside the sleeve and after compression has been applied to theoutside of the sleeve.

Figure 6 is a cross-sectional view similar. to Figure 3 but showsanother variation in the internai coating of my device.

Figure 7 is a view similar to Figure 6 showing still another variationin th internal coating of my device; and

Figure 8 is a view similar to Figure 7 showing two spray guns coatingthe sleeves.

the holding power of the-sleeve and another of l which increases theelectrical conductivity of the sleeve.

A further object of my invention is to furnish an attaching sleeve forconnection to a conductor and to provide a method whereby the electricalconductivity of the joint between the sleeve and the conductor can becontrolled during manufacture to assure that the conductivity of thejoint is equal to or greater than the conductivity'of the wire.

' Another object of my invention is to provide an electrical connectionfor a wire which has the greatest strength commensurate with thecohductivity desired in the connection.

Still another object of my invention is to provide an electricalconnection fora wire which has the largest electrical conductivitycommensurate with the strength desired in the connec: tion.

Other objects and a iulier understanding of my invention may be had byreferring to the following description and claims, takenin conjunctionfwith the accompanying drawing; in

which:

Figure 1- is an end view of a pluralityof my connecting sleeves arrangedin a holdingdevice With reference to the drawing, my. inventioncomprises coating the inner surface of a hollow metal sleeve M withseveral kinds of materials to increase the conductivity between thesleeve ill and a wire it without materially reducing the holding powerbetween the sleeve Ill and the wire l6.

One manner of coating the inner surface is illustrated in Figures 1 and2 or the drawing and consists of grouping together a plurality of thesleeves to be coated and spraying them with a material It which is tocover the inside surface For convenience I employ a container it at aslight angle with respect to the sleeves the operator assures that thematerial 15 strikes the inside wall surfaces.

After grouping the plurality of sleeves Iii in the container I2. theoperator tilts the. container at.

a slight angle for his convenience, as shown in Figure 2 and then hetakes his spray gun and directs the spray of material at a slight angleto there- V Figure 2 is a side view of the sleeves in Figure 1' orNichrome."

the longitudinal axisv of the inside surfaces of the sleeve so thatthesprayed material impingeathe sleeves for substantially one-half oftheir longitudinal length. The operator sprays all the sleeves withinthe container at this slight angle by sweeping the spray material overthe entire end surfaces of the plurality of sleeves within thecontainer. By directing the spray at a slight angle with respect to thelongitudinal axis of the openings in the sleeves ill the operatorinsures that the spray material impinges the inside surfaces of thesleeve to make a good coating which adheres firmly to the insidesurfaces of. the sleeves. Inasmuch as the spray is directed at a slightangle .to the longitudinal axis of the sleeve,

only a longitudinal arcuate portion of the inside surfaces of thesleeves is coated for each positional setting of the container l2 whichholds the plurality of sleeves. .To coat the entire inside surfaces iiiof the sleeves with the spray material, the operator rotates thecontainer substantially 90 degrees for each spraying operation. In thismanner the operator sprays a substantially 90 degree .arcuate surfacefor substantially onehalf of the length of the inside surfaces of thesleeves upon each positional setting of the container l2 which holds theplurality of -sleeves. After spraying the upper end of the sleeves III,the operator turns the container i2 end-for-end and repeats the sprayingprocess. Turning the container and the wire it are soft copper anyharder metal such as hard copper, bronze, stainless steel, or Nichromecould be used. If the sleeve layer the wire is is made of hard copperthe coating material i! could be of bronze, stainless steel If thesleeve it or wire it is made of bronze then onlyvthose metals which areharder than bronze, i. e., stainless steel, and Nichromc, could be used.a The other material which is sprayed on the inside surface ll of thesleeve in is preferably a metal having a high electrical conductivity.This high conductivity rlraetal is designatedby the reference characterIn sleeves having the entire inside surface coated with the hardmaterial il I have found a that the conductivity from'the wire it to esleeve iii is low as the metals which are t for their gripping qualitiesare poor in conductivity.

To produce a sleeve which is good in gripping and high in conductivity,therefore, I coat the inner surface ii with two kinds of metals, one

I! end-for-end and repeating the spraying process'is necessary for longsleeves as One material is harderthan by the balance betweenthe grippingaction and the conductivity between the wire and the sleeve. Thus, inthe spraying operation, the operator may spray a hard metal, forexample, for two 90- 'degree positions of the container i2 and thenconductivity between the sleeves and wire. The

metal coatings 17 and i8 sprayed insideof the sleeve are not smooth likeelectro-plating but consist of hills and valleys which keythemselvesinto the wire and sleeve when the sleeve I0 is squeezed intoengagement with the wire it.

In connecting the sleeve and the wire, the wire is inserted in thesleeve until it abuts the central stop i3, and then the sleeve iscompressed by any of the well known methods of rolling,

drawing, or Squeezing. For a squeezing operation, a constant movementclamping tool may be used to compress the sleeve l0 and the coatingstherein upon the wire l6 and force the coatings into intimate engagementwith the wire.

The pressure may be applied over spaced areas- 20, ll and 22 therebycausing substantially theentire inside surface In to engage the wire I.-

The hard coating 'i'l which lies on the surface of the sleeve i0 as isshown in Figure 4 is forced to dig into both the sleeve Ill and the wireI! by the squeezing of the clamping tool as may be seen in FiguredA-pull' on the wire IS with respect to the sleeve to will not cause thewire to pull out as the hard coating firmly grips boththe sleeve and thewire.

Electrical current flowing through the wire it will pass to the sleeve10 with a minimum of for strength or gripping qualities and one for,

conductivity.

To formmy improved sleeve, a portion of the inside surface of the sleeveis sprayed th. s

hard metal such as Nichrome'f and the remaining portion is sprayed witha metal ha a higher conductivity. The proportionate share of the insidesurface of the sleeve which is sprayed with the hard material and with.the material having a high conductivity is governed conduction loss asthe high conductivity coating is lies between the wire and the sleeveand is in close contact with each of them.

In the installation of current carrying wires where low loss byresistance is of importance my device has great utility. A wire which isto be connected to the sleeve has a known resistance and must withstanda known pull. With these values known the area inside the sleeve whichmust be covered by each of the coatings in order to meet the serviceconditions can readily be determined. l have illustrated in Figures 3, 6and 2 several variations in the amounts of the hard coating ill andconducting coating iii. Figure 3 shows half or the inside area coveredwith each of the difierent coatings. Figure a shows three-quarters ofthe inside area covered with a metal of high conductivity andone-quarter covered with the metal H which increases the gripping powerbetween the wire it? and the sleeve iii. This type may be used wherehigh conductivity is essential and the stress between the sleeve and thewire is low. Figure 7 shows a sleeve having three-quarters of its innersun. face i 6 covered with the hard metal iii and onlyv one-quartercovered with high conductivity metal is. This type of sleeve is to heused in connections where great strength is required to resist stress onthe wire with respect to the are'used simultaneously, one to spray thesleeve with the hard coating l1 and the other to spray the sleeve withthe conducting coating it. Each of the operators directs his spray tostrike the container I? at difierent angles and attempts to avoidspraying the same sleeves at the same. time as they each sweep the sprayover all the sleeves. As illustrated in Figure 8 the two spray guns itare held laterally apart and are directed at the sleeves in thecontainer from different sides thereby assuring that the metals l1 andit do not impinge on the same arcuate portion of the inside surface ofthe sleeves. I

Although I have described my invention as spraying molten metal in amanner to cause it to stick to the inside of a hollow sleeve it is to beunderstood that any means of coating the sleeve 1 is within the purviewof my application and that a sleeve on. which a plurality oi metals hasbeen painted or otherwise affixed is deemed a coated sleeve and withinthe scope or this disclosure.

with a molten metal which has a higher coefll-' cient of electricalconductivity than the said nickel chromium metal, inserting an endportionof the metal wire into an 'end portion of the sleeve andcompressing the sleeve and the coatings therein upon the wire. 1

2. The method of making a wire and sleeve joint of high strength and ofhigh electrical conductivity which comprises spraying a portion of theinner wall of'the sleeve with a molten metal comprised of nickel andchromium, spraying another portion of theinner walloi the sleeve withmolten bronze, inserting an end portion 0! the 7 metal wire into an endportion of thesleeve and compressing the sleeve and the sprayed metaltherein upon the wire.

3. The method of making a wire and sleeve joint of high strength and ofhigh electrical conductivity which comprises simultaneously spraying theinner wall of the sleeve with. a molten metal comprised of nickel andchromium and,

with molten bronze, inserting an end portion of the metal wire into anend portion of the sleeve and compressing the sleeve and the sprayedmetal therein upon the wire.

4. The method of making a wire and sleeve the metal of the sleeve or themetal ofthe wire to be joined, inserting an end portion of the wire intoan end portion of the sleeve and compressing the sleeve and the sprayedmaterial therein upon the wire to establish an electrical connectionwhich has a conductivity substantially equal to the conductivity of thewire which is joined.

5. A metal sleeve for joining an electrical conductor wire theretocomprising 'a hollow tubular sleeve having an inner surface, an area ofsaid inner surface being coated with a gripping material which is harderthan the metal of the said sleeve-and harder than the metal of the wiresto be joined and an area of saidinner surface being coated with amaterial'which is softer than said gripping material and which has ahigh,

coemcient of electrical conductivity, said second area having aconductivity substantially equal to' the conductivity of the wire to bejoined thereto.

6. A metal sleeve for Joining an electrical conductor wire theretocomprising ahollow tubular sleeve having an inner surface, an area ofsaid inner surface being coated with a gripping ma-j terial which isharder than the metal of the said sleeve and harder than the metal oithe wires to be Joined and an area of said inner surface being coatedwith a material which issofter than saidgripping material and which hasa high coefllcient oi el ctrical conductivity, said leeve having aresultant inner surface of the conductivity substantially equal to orbetter than the conductivity of the whom he joined thereto.

'l. A metal sleeve for joining an electrical conductor wire theretocomprising a hollow tubular sleeve having an inner surface, an area ofsaid inner surface being coated with a gripping ma-- terial comprisingnickel and chromium which is harder than the metal of the said sleeveand CHARLES E. KLEIN.

